Lu Dongdong, Mi Jiandui, Wu Yinbao, Liang Juanboo, Liao Xindi, Wang Yan
College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou 510642, China.
Animals (Basel). 2020 Nov 21;10(11):2172. doi: 10.3390/ani10112172.
Odour is one of the main environmental concerns in the laying hen industry and may also influence animal health and production performance. Previous studies showed that odours from the laying hen body are primarily produced from the microbial fermentation (breakdown) of organic materials in the caecum, and different laying hen species may have different odour production potentials. This study was conducted to evaluate the emissions of two primary odorous gases, ammonia (NH) and hydrogen sulphide (HS), from six different laying hen species (Hyline, Lohmann, Nongda, Jingfen, Xinghua and Zhusi). An in vitro fermentation technique was adopted in this study, which has been reported to be an appropriate method for simulating gas production from the microbial fermentation of organic materials in the caecum. The results of this study show that Jingfen produced the greatest volume of gas after 12 h of fermentation ( < 0.05). Hyline had the highest, while Lohmann had the lowest, total NH emissions ( < 0.05). The total HS emissions of Zhusi and Hyline were higher than those of Lohmann, Jingfen and Xinghua ( < 0.05), while Xinghua exhibited the lowest total HS emissions ( < 0.05). Of the six laying hen species, Xinghua was identified as the best species because it produced the lowest total amount of NH + HS (39.94 µg). The results for the biochemical indicators showed that the concentration of volatile fatty acids (VFAs) from Zhusi was higher than that for the other five species, while the pH in Zhusi was lower ( < 0.01), and the concentrations of ammonium nitrogen (NH), uric acid and urea in Xinghua were lower than those in the other species ( < 0.01). Hyline had the highest change in SO concentration during the fermentation processes ( < 0.05). In addition, the results of the correlation analysis suggested that NH emission is positively related to urease activities but is not significantly related to the ureC gene number. Furthermore, HS emission was observed to be significantly related to the reduction of SO but showed no connection with the aprA gene number. Overall, our findings provide a reference for future feeding programmes attempting to reduce odour pollution in the laying hen industry.
气味是蛋鸡养殖行业主要的环境问题之一，还可能影响动物健康和生产性能。先前的研究表明，蛋鸡体内的气味主要是由盲肠中有机物质的微生物发酵（分解）产生的，不同品种的蛋鸡可能具有不同的气味产生潜力。本研究旨在评估六种不同蛋鸡品种（海兰、罗曼、农大、京粉、杏花和竹丝）排放的两种主要臭气，即氨气（NH₃）和硫化氢（H₂S）。本研究采用了体外发酵技术，据报道这是一种模拟盲肠中有机物质微生物发酵产气量的合适方法。本研究结果表明，京粉在发酵12小时后产生的气体量最大（P<0.05）。海兰的总氨气排放量最高，而罗曼的最低（P<0.05）。竹丝和海兰的总硫化氢排放量高于罗曼、京粉和杏花（P<0.05），而杏花的总硫化氢排放量最低（P<0.05）。在这六个蛋鸡品种中，杏花被确定为最佳品种，因为它产生的NH₃+H₂S总量最低（39.94微克）。生化指标结果表明，竹丝的挥发性脂肪酸（VFA）浓度高于其他五个品种，而竹丝的pH值较低（P<0.01），杏花的铵态氮（NH₄⁺）、尿酸和尿素浓度低于其他品种（P<0.01）。海兰在发酵过程中SO₄²⁻浓度的变化最大（P<0.05）。此外，相关性分析结果表明，氨气排放与脲酶活性呈正相关，但与ureC基因数量无显著相关性。此外，观察到硫化氢排放与SO₄²⁻的还原显著相关，但与aprA基因数量无关。总体而言，我们的研究结果为未来旨在减少蛋鸡养殖行业气味污染的饲养方案提供了参考。
